Ammonia
Urea
Largely proteins, some amount of carbohydrates and fatty substances.
proteins are found in meat.
Proteins could be found in milk, fish, or chicken.
Proteins are synthesized by ribosomes in the cells by mRNA which codes the message of the amino acid sequence. Proteins found in diet is not going to directly act on our cells as they undergo digestion, only amino acids or other chemicals our cell gain. DNA in the nucleus controls the protein synthesis by gene expression.
Muscles
urea
There is no substance absolutely restricted to Earth (unless you count DNA, proteins, etc., but these are almost guaranteed to exist somewhere else).
The liver is the main organ involved in the deamination of amino acids. Deamination is the process of removing the amino group from amino acids to produce ammonia, which is then converted into urea for excretion.
Largely proteins, some amount of carbohydrates and fatty substances.
proteins are found in meat.
Proteins could be found in milk, fish, or chicken.
Proteins are synthesized by ribosomes in the cells by mRNA which codes the message of the amino acid sequence. Proteins found in diet is not going to directly act on our cells as they undergo digestion, only amino acids or other chemicals our cell gain. DNA in the nucleus controls the protein synthesis by gene expression.
Muscles
Surprisingly, membrane proteins are found in or attached to the membrane.
mitochondria
Ribosomes are the structures found on the ER that manufacture proteins.
Nitrogen is found in proteins but not in carbohydrates and lipids